# Configuration Overview

GoToSocial aims to be as configurable as possible, to fit lots of different use cases.

We try to provide sensible defaults wherever possible, but you can't run a GoToSocial instance without managing *some* configuration.

## Configuration Methods

There are three different methods for configuring a GoToSocial instance, which can be combined depending on your setup.

### Configuration File

The easiest way to configure GoToSocial is to pass a configuration file to to the `gotosocial server start` command, for example:

```bash
gotosocial --config-path ./config.yaml server start
```

The command expects a file in [YAML](https://en.wikipedia.org/wiki/YAML) or [JSON](https://en.wikipedia.org/wiki/JSON) format.

An example configuration file, with an explanation of each of the config fields, with default and example values, can be found [here](https://github.com/superseriousbusiness/gotosocial/blob/main/example/config.yaml). This example file is also included in release downloads. 

It's recommended to create your own configuration file with only the settings you need to change for your installation. This ensures you don't have to reconcile changes to defaults or adding/updating/removing settings from your configuration file that you haven't changed away from the defaults on every release.

### Environment Variables

You can also configure GoToSocial by setting [environment variables](https://en.wikipedia.org/wiki/Environment_variable). These environment variables follow the format:

1. Prepend `GTS_` to the config flag.
2. Uppercase-all.
3. Replace dash (`-`) with underscore (`_`).

So for example, instead of setting `media-image-max-size` to `2097152` in your config.yaml, you could set the environment variable:

```text
GTS_MEDIA_IMAGE_MAX_SIZE=2097152
```

If you're in doubt about any of the names of these environment variables, just check the `--help` for the subcommand you're using.

!!! tip "Environment variable arrays"
    
    If you need to use an environment variable to set a configuration option that accepts an array, provide each value in a comma-separated list.
    
    For example, `instance-languages` may be set in the config.yaml file as an array like so: `["nl", "de", "fr", "en"]`. To set the same values as an environment variable, use: `GTS_INSTANCE_LANGUAGES="nl,de,fr,en"`

### Command Line Flags

Finally, you can set configuration values using command-line flags, which you pass directly when you're running a `gotosocial` command. For example, instead of setting `media-image-max-size` in your config.yaml, or with an environment variable, you can pass the value directly through the command line:

```bash
gotosocial server start --media-image-max-size 2097152 
```

If you're in doubt about which flags are available, check `gotosocial --help`.

## Priority

The above configuration methods override each other in the order in which they were listed.

```text
command line flags > environment variables > config file
```

That is, if you set `media-image-max-size` to `2097152` in your config file, but then *ALSO* set the environment variable `GTS_MEDIA_MAX_IMAGE_SIZE=9999999`, then the final value will be `9999999`, because environment variables have a *higher priority* than values set in config.yaml.

Command line flags have the highest priority, so if you set `--media-image-max-size 13121312`, then the final value will be `13121312` regardless of what you've set elsewhere.

This means in cases where you want to just try changing one thing, but don't want to edit your config file, you can temporarily use an environment variable or a command line flag to set that one thing.

## Default Values

Reasonable default values are provided for *most* of the configuration parameters, except in cases where a custom value is absolutely required.

See the [example config file](https://github.com/superseriousbusiness/gotosocial/blob/main/example/config.yaml) for the default values, or run `gotosocial --help`.
